This invention relates to a data transmission system and a data transmission method for carrying out transmission of data and a data receiving apparatus and a data receiving method for receiving data, and more particularly to a data transmission system and a data transmission method for carrying out transmission of data by relaying, etc. and a data receiving apparatus and a data receiving method for receiving data by relaying, etc.
In recent years, in the broadcasting station, as a method of quickly carrying out transmission of editing material or news gathering material, satellite news gathering (SNG) system has been offered. In general, as this SNG system, there is provided the system of initially carrying out digital modulation of material to be transmitted at the sending-out side of material to carry out transmission thereof to the broadcast station by using the satellite channel, and to further carry out, at the receiving side of material, digital demodulation of material which has been transmitted to edit the demodulated material to thereby generate video program.
This SNG system is used for sending material such as gathered image gathered at the field to the central broadcast station, or is used for carrying out transmission of program material edited at the central broadcast station from the central broadcast station to the regional or local broadcast station.
The broadcast station must pay utilization charge of this satellite channel by the satellite channel used for carrying out transmission of material by using this SNG and the time at which its satellite channel is used.
Since the transmission unit using the conventional SNG system required one transponder, i.e. one satellite channel for the purpose of carrying out transmission of one material, it has the problem that cost for lending transponders of plural channels becomes high in order to simultaneously carry out, e.g., on the real time basis, transmission of plural live images prepared at the field to the central broadcast station.
Moreover, in order to carry out transmission of field of, e.g., two hours from the field to the central broadcast station, it is necessary to occupy the satellite channel over two hours and the cost required for lending transponder becomes burden according as the time of material becomes longer.
Meanwhile, in the data communication, etc., the data receiving unit is used as the relaying transmitting unit to have ability to transmit data to the remote place. However, there are instances where, as data inputted to such data receiving unit, plural kinds of data are multiplexed. Further, data inputted in the multiplexed state are selectively read by respective receiving sections of the data receiving unit. Data are read in the state selected every data of the same kind, e.g., transmission destination by the respective receiving sections. Data which have been read into respective receiving sections in this way are transmitted toward equipments of respective destinations through the relaying receiving unit.
Reading operations every various kinds of data by respective receiving sections of the data receiving unit were carried out by setting in advance the receiving section in a manner to be in correspondence with destinations to be transmitted of respective data transmitted to the data receiving unit. For example, user carried out in advance setting operations of respective receiving sections caused to be in correspondence with destinations of respective data in a manner caused to be in correspondence with respective data inputted to the data receiving unit.
In this case, there are many instances where data inputted to the data receiving unit are changed, e.g., destinations of data are changed. User is required to set, for a second time, respective receiving sections in a manner caused to be in correspondence with that change. However, in the case of a method of setting respective receiving sections every time in a manner caused to be in correspondence with change of inputted data, convenience of use becomes poor.
This invention has been made in view of the above-described actual circumstances, and its object is to provide a transmission system and a transmission method in which one satellite channel is used to carry out transmission of video data of plural channels to carry out transmission of material at a high speed, and a data receiving apparatus and a data receiving method in which there is no necessity of setting the receiving unit in advance in a manner caused to be in correspondence with inputted data.
In order to solve the above-described problems, a data transmission method according to this invention includes, in a transmission system for carrying out transmission of video data of plural channels, encoding means for respectively encoding the video data of the plural channels, format converting means for inserting video data of plural channels encoded by the encoding means into payload portion of a predetermined serial transmission format to thereby convert format of the video data of the plural channels, multiplexing means for multiplexing video data of plural channels which have been caused to undergo format conversion by the format converting means, and transmission means for carrying out transmission of data multiplexed by the multiplexing means.
Moreover, a transmission system according to this invention is directed to a transmission system caused to be of configuration including a transmitting unit for transmitting video data and a receiving unit for receiving video data which has been transmitted from the transmitting unit, the transmitting unit including encoding means for encoding the video data, high speed reproducing means for reproducing, at speed of N times, video data encoded by the encoding means, format converting means for converting video data of N times speed reproduced by the high speed reproducing means into data of format for a predetermined serial transmission in order to carry out transmission thereof at rate corresponding to the N times speed, and transmission means for carrying out transmission of data which has been caused to undergo format conversion by the format converting means at rate corresponding to the N times speed; and the receiving unit including receiving means for receiving video data of N times speed which has been caused to undergo transmission at rate corresponding to the N times speed from the transmission means and high speed recording means for recording, at N times speed, the received video data of N times speed.
A transmission method according to this invention includes, in a transmission method for carrying out transmission of video data of plural channels, a step of respectively encoding the video data of plural channels to thereby generate encoded video data of plural channels, a step of inserting the encoded video data of plural channels into payload portion of a predetermined serial transmission format to thereby generate video data converted into the predetermined serial transmission format, a step of multiplexing the video data of plural channels converted into the predetermined serial transmission format to thereby generate the multiplexed video data of the predetermined serial transmission format, and a step of carrying out transmission of the multiplexed data of the predetermined serial transmission format.
A transmission method according to this invention is directed to a transmission method for carrying out transmission of video data of a transmitting unit for transmitting video data to a receiving unit, the method being adapted to reproduce, at the transmitting unit side, encoded video data at N times speed to convert video data reproduced at N times speed into data of format for a predetermined serial transmission for the purpose of carrying out transmission thereof at rate corresponding to the N times speed to carry out transmission of video data of N times speed which has been caused to undergo format conversion at rate corresponding to the N times speed from the transmitting unit to the receiving unit, and to receive, at the receiving unit side, video data of N times speed which has been caused to undergo transmission at rate corresponding to the N times speed from the transmission means to record the received video data of N times speed at N times speed.
A data receiving apparatus according to this invention comprises destination information reading means for reading out all destination address information of input data, receiving means adapted so that predetermined receiving addresses are set to receive data of corresponding set one of the receiving addresses within the input data, and address setting means for setting receiving address at the receiving means on the basis of destination address information that the destination information reading means has read out.
The data receiving apparatus constituted in this way receives data every destination by the receiving means in which receiving addresses are set by address setting means on the basis of destination address information that the destination information reading means has read out.
A data receiving method according to this invention includes a destination information reading step of reading out all destination address information of input data, an address setting step of setting receiving address of receiving means on the basis of the destination address information which has been read out at the destination information reading step, and receiving step of receiving data of corresponding set one of the receiving addresses of the input data by the receiving means set to a predetermined receiving address at the address setting step.
The data receiving method featured above is adapted to receive data every destination at the receiving step by the receiving unit in which receiving addresses are set at address setting step on the basis of destination address information which has been read out at the destination information reading step.